1. Field of the Invention
The present invention relates to a diagnostic system for a jacquard machine, in particular, a jacquard machine for a weaving loom.
2. Description of the Related Art
Jacquard machines for weaving looms usually include a plurality of heald hooks arranged in rows extending in the weft direction, the rows being located side by side in the warp direction.
Each row of hooks is acted upon by a reciprocating knife such that selected hooks in the row are moved from one shed position to and held at another shed position during a pick in the weaving cycle. Depending upon the type of jacquard machine, the knife may move only selected hooks from said one shed position or may move all hooks from said one shed position such that selected hooks can be retained at said one shed position.
In order to ensure that fabric being woven has no faults caused by failure to select a chosen heald hook it is known to provide detection means which act to produce a signal should the chosen heald hook not be selected. Such detection means are usually in the form of mechanically operated electrical switches and these tend to be unreliable. In addition, in a Jacquard machine, there can be several thousand heald hooks and so the use of mechanical switches becomes increasingly more unsatisfactory and costly.